content instance view permissions are secondary to page view permissions. Most of the time you should not bother setting anything in the content instance view roles and just use page view roles from page settings. The only real use for content instance view roles is if you want users to be able to view a page but not a view an instance on the page without being in a role. ie if the user can view the page but the instance has more restrictive view roles that he is not in the content instance will not be shown on the page for that user. If a user has view permissions on a content instance but not on the page containing the content instance then he cannot view the content. So really page view roles are the primary security mechanism and content instance view roles are just supplemental to page roles.

So in short to solve your problem go to page settings for the page that contains the forums and make the page view permissions allow authenticated users.

Hope that helps,

Joe

Just so you know, under the "security" tab on the module settings, there are radio buttons as well as check boxes. It's possible you checked the "All users" or "authenticated users" check boxes but left the "Only Adminstrators are allowed" radio button checked.

Make sure the "Administrators, Content Administrators, and roles selected below are allowed." radio button is checked as well as the "All users" or "authenticated users" check boxes.

Just pointing it out cause it might be easy to overlook.